QT中菜单Menu与工具栏Toolbar中各个Action的动态添加删除

就像Swing里面的Action一样，Qt里面也有一个类似的类，叫做QAction。顾名思义，QAction类保存有关于这个动作，也就是action的信息，比如它的文本描述、图标、快捷键、回调函数(也就是信号槽)，等等。神奇的是，QAction能够根据添加的位置来改变自己的样子——如果添加到菜单中，就会显示成一个菜单项；如果添加到工具条，就会显示成一个按钮。

代码如下：

//MainWindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include 

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT
    
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

public slots:
    void openFile();
    void add();
    void remove();
private:
    Ui::MainWindow *ui;
    //QAction *openAcition;
    QMenu *file;
    QAction *addscess;
    QToolBar *toolbar;
    QToolBar *toolbar1;
};

#endif // MAINWINDOW_H

//MainWindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include 

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    QAction *openAcition = new QAction(tr("&Open"),this);
    QAction *openAction = new QAction(tr("&apen"),this);
    QAction *add = new QAction(tr("&add"),this);
    QAction *remove = new QAction(tr("&remove"),this);

    file = menuBar()->addMenu(tr("&File"));
    file->addAction(openAcition);
    file->addAction(add);
    file->addAction(remove);


    toolbar = addToolBar(tr("&File"));
    toolbar->addAction(openAcition);
    toolbar->addAction(openAction);

    toolbar1 = addToolBar(tr("&File"));
    //toolbar1->addAction(openAcition);
    toolbar1->addAction(openAction);


    connect(openAcition,SIGNAL(triggered()),this,SLOT(openFile()));
    connect(add,SIGNAL(triggered()),this,SLOT(add()));
    connect(remove,SIGNAL(triggered()),this,SLOT(remove()));
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::openFile()
{
    qDebug()<<"I did that!!";
}

void MainWindow::add()
{
    addscess = new QAction(tr("&addscess"),this);
    file->addAction(addscess);
    toolbar->addAction(addscess);
}

void MainWindow::remove()
{
    file->removeAction(addscess);
    toolbar->removeAction(addscess);
}